This invention relates to a method for positioning and bonding components of a high precision optical system or the like.
A known photographic picture density data recording apparatus (densitometer) for a picture printing unit comprises a light source for illuminating an original negative or positive film for printing (although hereafter only a "negative" will be referred to); light receiving storage elements arranged in a planar configuration facing the negative; and an optical system for forming the image of the negative on the light receiving elements.
FIG. 1 is a side view outlining the above-described apparatus. A light source 2 illuminates a negative 1. A filter plate 3 has three color separating filters R, G, and B. The filter plate 3 is rotatable around a shaft 3A. One example of the filter plate 3 is shown in FIG. 2. A projecting lens 4 receives the light transmitted through the filter plate 4. A light receiving unit 5 comprises charge coupled devices (CCDs) arranged in a plane. The light receiving unit 5 is made up of 350 CCDs for instance for imaging 135 type film (the so-called 35 mm film). The CCDs are arranged with fourteen elements along the short side of the image and twenty-five elements along the long side.
It is essential for the above-described densitometer to accurately form the image of the negative film on the light receiving unit 5 by means of the lens 4 for a long period. However, since the light receiving unit 5 is very small (for instance 1.25 mm long and 0.7 mm wide), in forming the image of the negative on the light receiving unit 5, it is very difficult to position the lens 4 and the light receiving unit 5 for instance with a distance of about 3 mm therebetween, and to fix the parts thus positioned. Especially, where adhesive is applied to bond together the parts which have been positioned, the parts are greatly displaced by the inherent contraction of the adhesive. This presents a serious problem for the apparatus.